The increasingly widespread use of underground power distribution systems has led to the development of larger systems utilizing components designed to handle greater amounts of power. Electrical power is typically distributed through cables that are connected to other cables and electrical equipment in the system. Separable loadbreak and deadbreak connectors and accessories provide a convenient method to connect and disconnect cables and equipment in underground power distribution systems.
A variety of different connectors and accessories are used in power distribution systems, such as separable elbow connectors, cable joints, bushings, inserts, links, cable terminations and other mating components. Electrical connectors developed for use in such systems can accommodate approximately 5 kV to 35 kV. Loadbreak elbows include provisions for energized operation using standard hotstick tools, allowing load-make and break operation and a visible disconnect. Components can be isolated with insulated caps, plugs and parking bushings. Optional accessories allow system grounding, testing, bypass, lightning surge protection and current limiting fusing. Additional connecting points and taps can be provided using junctions or feed-thrus.
The connectors for high voltage power distribution systems must be designed so that they can be manipulated by an operator at a safe distance from the connection to the high voltage electrical apparatus. To accomplish this, an insulated tool known as a “hot-stick” is used to install and service the connectors. The hot-stick allows the operator to connect, disconnect and maintain the various components in the system from a safe distance of at least 4 or 5 feet.
Proper maintenance procedures in high voltage cable systems require a circuit to be de-energized and isolated by opening switches or disconnecting the cable at both ends of the cable run. The circuit is then tested to ascertain that it is actually de-energized and each phase is grounded at both ends to prevent injury should the cable system accidentally become energized. Finally, the cables are removed from the switch or transformer bushings to achieve a visible break between the cables and their respective bushings.
In underground power distribution systems, electrical power is typically transmitted from substations through cables which interconnect other cables and electrical apparatus in a power distribution network. The cables are typically terminated on bushings that may pass through walls of metal encased equipment such as capacitors, transformers or switchgear. High voltage, separable connector systems have been developed that allow disconnection of the electrical path from a deadfront apparatus to the feeder cables connected to the apparatus bushings without moving the feeder cables and while providing visible-break isolation. The connector systems typically include a removable link or connector located between a deadfront junction mounted to the electrical apparatus and a mating connector (such as an elbow connector) joined to a cable.
The connectors (also referred to herein as “links”) presently in use have bushing inserts (i.e., male connectors) that require a bushing extender and a reducing tap well in order to connect to a bushing or a feed-thru insert. One end of the reducing tap well is connected to the male interface of the bushing or feed-thru insert and the other end is connected to a bushing extender. The bushing extender is then connected to a bushing insert on a link connector.
FIGS. 1 and 2 show a prior art hotstick operable link connector 910 that has a housing 912 with two bushings 914, 916 extending from the bottom surface 918 and a third bushing 920 extending from the top surface 922. The connector 910 is attached to a feed-thru insert 924 using a bushing extender 926. After the prior art connector 910 is connected to the feed-thru insert 924, the total distance (“X”) from the bottom of the connector 910 to the top of the feed-thru insert 924 is increased because the bushing extender 926 has to be used.
The multiple components in the link connectors presently being used require additional assembly time and increase the length of the connector assembly. In applications where space is limited, the increased length of the connector assembly can be a problem when installing and maintaining the connector assembly. Therefore, there is a need for a connector assembly with fewer components and a shorter overall length.